Have you ever torn open an Ethernet jack? We’d bet the vast majority of readers — even the ones elbow-deep into the hardware world — will answer no. So we applaud the effort in this one, but the conclusion landed way off the mark.
In the last few days, a Tweet showing a Raspberry Pi with its Ethernet socket broken open suggested the little PCB inside it is a hidden bug. With more going on inside than one might expect, the conclusion of the person doing the teardown was that the Raspberry Pi foundation are spying upon us through our Ethernet traffic. That’s just not the case. But we’re still excited about what was found.
Hackers, Designers, and Engineers flooded into Dom Omladine on Saturday for what can only be described as an epic celebration of hardware culture. This is the second time Hackaday has organized a huge conference in Belgrade, and lightning really did strike twice.
A Gathering of New Friends and Old
We got things started off with a meetup the night before the conference. The first Hackaday Belgrade was held in 2016 and we didn’t reserve a bar on Friday night — we ended up taking over one just through sheer numbers. This year we called ahead for a large outdoor space, then made good use of it.
A great kickoff to the weekend
LED cube animation emulation demo
*No beers were wasted during this meetup
Everyone was giddy with anticipation of the next day to come. There is always a sizzling energy of meeting up in real life. Most of this group hangs out on Hackaday.io, but only some of them have met in person. Add to that the reunions of those who became friends at the previous Hackaday Belgrade and at other cons around Europe and you have the feeling of coming home. These really are your people.
Yes, a Conference. But the Cool Kind
Hackaday conferences are more than just parties… they’re conferences. If you approach it the right way you can get your employer on board with you attending because you’re going to meet incredible people, learn lots of stuff, and come back excited to take on the Universe. Actually, bring your boss along for the ride too!
Flooding into Hackaday Belgrade
Breakfast spread as the doors open
This year we had thirteen incredible talks. As is our practice, we started off with a super-technical talk as Rachel Wong (aka @konichiwakitty) discussed her Ph.D research which involves growing eye tissue in the lab. But like all incredibly brilliant minds, she has a creative outlet which she also covered as part of her Keynote address. Rachel has a passion for building wearables that are reaching for the future by embracing things we really do need in our garments and gear.
Main hall packed for the keynote address
The workshop area full to the brim
From drone monitoring networks to robot soldering machines, and concepts for designing meaningful hardware to using code to automate tedious PCB layout, there was plenty in these talks for everyone.
Rachel Wong on the growing of eye tissue
Elliot Williams demos Logic Noise live on stage
I really enjoyed Elliot Williams’ talk on Logic Noise for his live demos using simple logic chips to build up complex music. Marcel van Kervinck took us on a journey of TTL computer design. And Sophi Kravitz’s talk on building non-rigid airships had at least two people at the con get inspired and spin their own blimp design during the conference! There was a live-feed of the talks so keep your eye on Hackaday as we pull those out to be featured individually.
Some of the demo hardware: Acoustic levitation for lab work
The workshops were standing room only as people who weren’t able to grab a ticket audited the course. We had three hands-on session that built wearable circuitry, brough art to PCB design, and dove into the world of FPGAs.
Welcome, Here’s Your Neck-Mounted Retro Computer
Everyone through the door received a custom electronic badge to hack on during Hackaday Belgrade. Voja Antonic designed the hardware and oversaw the manufacture. We had excellent yield which is great because we had nearly (if not more than) 100% attendance at the conference. We ended the day with just 5 badges to spare!
These handheld computers are truly hot! The badges each have 55 really clicky keys. With at least 350 people in the room, that’s approaching 20k momentary push switches and at one point, a brief “silence” fell and all that could be heard were clicking buttons. That and we asked everyone to play the Mario Overworld tune at the same time as hundreds of badges rose in a glorious chorus. There’s also a 16-page user manual to go along with them which included sample code to get started.
Hacking went on throughout the day but as the talk session wrapped up we transformed the hall into a Hacker Village. Tables were brought in and immediately filled. Live music filled the room as Bogdan Rosu and Richard Hogben each played IDM sets. If you’ve been watching Hackaday videos you’ve heard their work and their performances this night were epic.
What is better than hacking to live music?
Still going strong as midnight approaches
Rich and Bogdan join forces for the final live music set
So much hacking, so little time
Head to head game called ‘Shoot my Valentine’
Head to head Tic Tac Toe
There were other hardware demos on display too
This badge was put on WiFi by lunchtime
[Flummer]’s badge displays minimalist style
Detail of [Larissa Koncz]’s Interactive Poetic Glove from the workshop
The world’s slowest sinewave, calculated in BASIC: [Tom van Dijk]
So much ASCII art!
[Frederic] and [Manoel] got their badges talking over AFSK, when the RF interference didn’t get them…
The RevSpace crew at work in the quiet workshop room
There was food, there was beer, and there were the tools of our lifestyle; laptops, programmers, jumper wires, blinky add-ons, and the excitement that goes along with all of them. The badge hacking presentations began at midnight and the place was still alive with excitement. It is truly great to see how supportive our community is of exploring hardware and trying things out. Publish your badge hacks and stories from the conference on Hackaday.io as we’ll be featuring those in the coming days and want to make sure we have all the juicy details.
Why Belgrade?
Keep your eye on Hackaday as there is much more coverage to come on this wonderful event. Many have asked: “Why Belgrade?”. It’s a fantastic city and the engineering community in the area is passionate about getting together to learn and share ideas. This includes the Supplyframe engineers who live in Belgrade and did the heavy lifting to organize and staff Hackaday Belgrade. You all did an amazing job and everyone at the con owes you a debt of gratitude, thank you so much! We also want to thank Supplyframe and SevenBridges, our sponsors for the event.
To all who attended, it wouldn’t have happened without you! I can speak for everyone on the Hackaday crew in saying the culture we share is energizing, encouraging, and humbling. It’s exactly the kind of recharge everyone looks for to keep life interesting! We’ll see you at the next one. Now over the next five months we have our sights set on the Hackaday Superconference. See you there!
If you’ve done anything with a modern Linux system — including most variants for the Raspberry Pi — you probably know about sudo. This typically allows an authorized user to elevate themselves to superuser status to do things.
However, there is a problem. If you have sudo access, you can do anything — at least, anything the sudoers file allows you to do. But what about extremely critical operations? We’ve all seen the movies where launching the nuclear missile requires two keys counter-rotated at the same time and third firing key. Is there an equivalent for Linux systems?
It isn’t exactly a counter-rotating key, but the sudo_pair project — a prelease open-source project from Square — gives you something similar. The project is a plugin for sudo that allows you to have another user authorize a sudo request. Not only do they authorize it, but they get to see what is happening, and even abort it if something bad is happening.
Some of the best hacks are the ones which seem perfectly obvious in hindsight; a solution to the problem that’s so elegant, you wonder how it never occurred to you before. Of course we also love the hacks that are so complex your eyes start to water, but it’s nice to have a balance. This one, sent in by [Eduardo Zola] is definitely in the former group.
In the video after the break, [Eduardo] demonstrates his extremely simple setup for using ultrasonic transducers for one-way data communication. Powered by a pair of Arduinos and using transducers salvaged from the extremely popular HC-SR04 module, there’s a good chance a lot of readers can recreate this one on their own bench with what they’ve got lying around. In this example he’s sending strings of text from one computer to another, but with a little imagination this can be used for all sorts of projects.
For the transmitter, the ultrasonic transducer is simply tied to one of the digital pins on the Arduino. The receiver is a bit more complex, requiring a LM386 amplifier and LM393 comparator to create a clean signal for the second Arduino to read.
But how does it work? Looking through the source code for the transmitter and receiver, we can see it’s about as basic as it gets. The transmitter Arduino breaks down a given string into individual characters, and then further converts the ASCII to eight binary bits. These bits are sent out as tones, and are picked up on the receiving end. Once the receiver has collected a decent chunk of tones, it works through them and turns the binary values back into ASCII characters which get dumped over serial. It’s slow, but it’s simple.
CubeSats are tiny satellites which tag along as secondary payloads during launches. They have to weigh in at under 1.33 kg, and are often built at low cost. There’s even open source designs for these little spacecrafts. Over 800 CubeSats have been launched over the last few years, with many more launches scheduled in the near future.
[Thomas Cholakov] coupled a homemade cloverleaf antenna to a software-defined radio to track some of these satellites. The antenna is built out of copper-clad wire cut to the correct length to receive 437 MHz signals. Four loops are connected together and terminated to an RF connector.
This homebrew antenna is connected into a RTL-SDR dongle. The dongle picks up the beacon signals sent by the satellites and provides the data to a PC. Due to the motion of the satellites, their beacons can be easily identified by the Doppler shift of the frequency.
[Thomas] uses SDR Console to receive data from the satellites. While the demo only shows basic receiving, much more information on decoding these satellites can be found on the SDR Satellites website.
This looks like a fun weekend project, and probably the cheapest aerospace related project possible. After the break, watch the full video explaining how to build and set up the antenna and dongle.
There are a bunch of FPGA development boards to choose from, but how many will fit inside your laptop? The PicoEVB is a tiny board that connects to a M.2 slot and provides an evaluation platform for the Xilinx Artix-7 FPGA family.
This minimalist board sports a few LEDs, a PCIe interface, an integrated debugger, on-board EEPROM, and some external connectors for hooking up other bits and pieces. The M.2 connector provides the board with power, USB for debugging, and PCIe for user applications.
A major selling point of this board is the PCIe interface. Most FPGA boards with PCIe will cost over a grand, and will only fit in a large desktop computer. The lower priced options use older FPGAs. The PicoEVB is tiny and retails for $219. Not a bad deal when the FPGA on-board costs nearly $100.
The PicoEVB is also open source. Design files and sample projects can be found on Github.
Getting bounced to a website by scanning a QR code is no longer an exciting feat of technology, but what if you scanned the ingredient list on your granola bar and it went to the company’s page for that specific flavor, sans the matrix code?
Bright minds at the Columbia University in the City of New York have “perturbed” ordinary font characters so the average human eye won’t pick up the changes. Even ordinary OCR won’t miss a beat when it looks at a passage with a hidden message. After all, these “perturbed” glyphs are like a perfectly legible character viewed through a drop of water. When a camera is looking for these secret messages, those minor tweaks speak volumes.
The system is diabolically simple. Each character can be distorted according to an algorithm and a second variable. Changing that second variable is like twisting a distorted lens, or a water drop but the afterimage can be decoded and the variable extracted. This kind of encoding can survive a trip to the printer, unlike a purely digital hidden message.
Hidden messages like these are not limited to passing notes, metadata can be attached to any text and extracted when necessary. Literature could include notes without taking up page space so teachers could include helpful notes and a cell phone could be like an x-ray machine to see what the teacher wants to show. For example, you could define what “crypto” actually means.
![[Flummer]'s badge displays minimalist style](https://i0.wp.com/hackaday.com/wp-content/uploads/2018/05/dscf0774.jpg?w=242&h=182&ssl=1 "DSCF0774")
![Detail of [Larissa Koncz]'s Interactive Poetic Glove from the workshop](https://i0.wp.com/hackaday.com/wp-content/uploads/2018/05/dscf0785.jpg?w=242&h=181&ssl=1 "DSCF0785")
![The world's slowest sinewave, calculated in BASIC: [Tom van Dijk]](https://i0.wp.com/hackaday.com/wp-content/uploads/2018/05/dscf0776.jpg?w=225&h=168&ssl=1 "DSCF0776")
![[Frederic] and [Manoel] got their badges talking over AFSK, when the RF interference didn't get them...](https://i0.wp.com/hackaday.com/wp-content/uploads/2018/05/dscf0748_bright.png?w=126&h=168&ssl=1 "DSCF0748_bright")
